Howard Ian P, Fujii Yoshitaka, Allison Robert S
Centre for Vision Research, York University, Toronto, Canada.
J Vis. 2014 Feb 19;14(2):14. doi: 10.1167/14.2.14.
Information about the motion in depth of an object along the midline of a stationary observer is provided by changes in image size (looming), changes in vergence produced by changes in binocular disparity of the images of the object, and changes in relative disparity between the moving object and a stationary object. Each of these cues was independently varied in the dichoptiscope, which is described in Howard, Fukuda, and Allison (2013). The stimuli were a small central dot and a textured surface moving to and fro in depth along the midline. Observers tracked the motion with the unseen hand. Image looming was normal or absent. The change in vergence was absent, normal, more than normal, or reversed relative to normal. Changing relative disparity between the moving stimulus and a stationary surface was present or absent. Changing vergence alone produced no motion in depth for the textured surface but it produced some motion of the dot. Looming alone produced strong motion in depth for the texture but not for the dot. When the direction of motion indicated by looming was opposite that indicated by changing relative disparity observers could use either cue. The cues dissociated rather than combined.
沿着静止观察者的中线，物体在深度上的运动信息由图像大小的变化（逼近）、物体图像双眼视差变化所产生的辐辏变化以及运动物体与静止物体之间相对视差的变化提供。在霍华德、福田和艾利森（2013年）所描述的双色镜中，这些线索中的每一个都被独立改变。刺激物是一个位于中心的小点和一个沿着中线在深度上来回移动的有纹理的表面。观察者用未被看到的手跟踪运动。图像逼近正常或不存在。辐辏变化不存在、正常、大于正常或相对于正常情况反转。运动刺激物与静止表面之间的相对视差变化存在或不存在。单独改变辐辏不会使有纹理的表面产生深度运动，但会使小点产生一些运动。单独的逼近会使有纹理的表面产生强烈的深度运动，但不会使小点产生深度运动。当逼近所指示的运动方向与相对视差变化所指示的方向相反时，观察者可以使用任何一个线索。这些线索是分离的而不是组合的。
